The present invention relates to telecine video signal detectors in color television receivers and, more specifically, to a telecine video signal detector capable of sequentially detecting even an insuccessive telecine video signal produced due to editing or the like.
In recent years, various video reproducing methods are available in television, and the need for improving image quality is growing more. When video signals are reproduced through sequential scanning of interlace signals, the importance lies in detection of a telecine video signal produced through conversion from 24-frame film video to an interlace signal with the use of a 2-3 pulldown scheme and recovery of the signals corresponding to the video before telecine conversion, for the purpose of suppressing deterioration in image quality due to interlacing, and improving image quality.
Shown in FIG. 13 is the structure of a conventional telecine video signal detector. A telecine video signal detector Dtc includes a pre-filter 100, a 1-frame delay circuit 120, a motion vector detection circuit 140, a comparison and detection circuit 160, a majority circuit 180, a 5-field delay circuit 200, and a decision circuit 220. The pre-filter 100 eliminates noise in a video signal Svxe2x80x2 provided from an external video signal source (not shown) to the telecine video signal detector Dtc to produce a video signal Sv. The 1-frame delay circuit 120 delays the video signal Sv produced by the pre-filter 100 by one frame (2 fields) to produce a delayed video signal Svd.
The motion vector detection circuit 140 compares the delayed video signal Svd produced by the 1-frame delay circuit 120 and the present video signal Sv each other for detecting a motion of video between fields, and then produces a plurality of motion vectors Sm.
The comparison and detection circuit 160 compares the plurality of motion vectors Sm produced by the motion vector detection circuit 140 with a reference value (xcex1, xcex2). The comparison and detection circuit 160 then outputs, as small-motion vectors Sms, motion vectors that are smaller than the reference value (xcex1, xcex2) among the motion vectors Sm.
The majority circuit 180 takes frequency distribution of the small-motion vectors Sms outputted from the comparison and detection circuit 160, detects the small-motion vectors equal in size, and provides the detection result to the 5-field delay circuit 200 and the decision circuit 220.
The decision circuit 220 counts the number of small-motion vectors Sms equal in value that are not larger than the reference value (xcex1, xcex2), and generates a decision signal SF for deciding that the video signal is a telecine video signal, every time a field in which the number of small-motion vectors is not smaller than a predetermined value xcex3 appears for every five fields.
In the above-structured conventional telecine video signal detector Dtc, attention is given to the field in which the number of motion vectors equal in value for one frame (two fields) are not smaller than the predetermined value. When such field appears for every five fields, it is decided that the video signal is a telecine video signal. This decision concept will be further described later with reference to FIG. 14.
With reference to FIGS. 14, 15, and 16, a decision operation in the decision circuit 220 of the telecine video signal detector Dtc is now described in detail. Shown in FIG. 14 are various signals observed in the decision circuit 220.
First, in FIG. 14, Cc1 through Cc22 shown in the top row each represent a control cycle in the telecine video signal detector Dtc. Note that, in the present example, the control cycles Cc1 through Cc22 each correspond to a field period of the video signal Sv. The video signal Sv is provided for every field period in order of field data A1, A2, B1, B2, B1, C2, C1, D2, D1, D2, E1, E2, F1, F2, F1, G2, G1, H2, H1, J2, K1, L2, . . .
Each field data is identified by an identifier generated by adding a numerical suffix to a letter of the alphabet. Each alphabet letter represents an original image from which the data is generated, while each numerical suffix represents a position of the data field in those generated from the same image. In other words, in the above-stated video signal Sv, the alphabet letters A, B, C, D, E, F, G, H, J, K, and L each represent field data of each independent image. As stated above, pieces of field data represented with different suffixes (1 and 2) added to the same alphabet are originally generated from the same film image and, naturally, the difference in motion of the image is extremely small between fields. Furthermore, pieces of field data with the same identifier are the same image. Thus, such pieces of field data represented by identifiers with the same alphabet but different suffixes are hereinafter referred to as same-source field data.
In view of the above, in the video signal Sv, the same-source field data A1 and A2 generated from the same image are placed in the control cycles Cc1 and Cc2, respectively. Then, identical pieces of same-source field data B1 are placed in the following control cycles Cc3 and Cc5. In the control cycle Cc4 therebetween, the field data B2 generated from the same image as that for the filed data B1 is placed.
Similarly, the same-source field data C1 and C2 are placed in the control cycles Cc6 and Cc7; the same-source field data D2 and D1 in the control cycles Cc8 and Cc9, respectively; and the field data D2 that is identical to the field data D2 (generated from the same source as that for the field data D1) in the control cycle Cc10.
The above-described scheme is called a 2-3 pulldown scheme, which is a method of converting film video data differed in frame rate into television video data in such a manner that two pieces of same-source field data and three pieces of another same-source field data (of three, two at both ends are identical field data) are placed every successive five fields. The above-stated successive five fields are hereinafter referred to as a telecine video unit Tu.
In this case, the video signal Sv is a telecine video Vt during the control cycles Cc1 through Cc 19, while a non-telecine video Vnt during the control cycles Cc20 through Cc22. The control cycles Cc1 through Cc5 form a telecine video unit Tu1; the control cycles Cc6 through Cc10 form a telecine video unit Tu2; the control cycles Cc11 through Cc15 form a telecine video unit Tu3; and the control cycles Cc16 through Cc19 form a telecine video unit Tu4. Note that the telecine video unit Tu4 is constructed of not five fields, but four fields. That is, the image field data J2 is placed in the control cycle Cc20, in stead of the field data H2 which is identical to the field data one frame (two fields) before and is supposed to be placed at part (tail end) of the telecine video unit Tu4. In other words, shown in FIG. 14 is one example in which the telecine video Vt is switched into the non-telecine video Vnt in an incomplete state (the telecine video unit Tu of four fields).
The telecine video Vn is produced by converting cinema images of 24 frames/second into interlaced television video of 30 frames (60 fields) through the 2-3 pulldown scheme. The non-telecine video Vnt is interlaced images of 30 frames (60 fields)/second or progressive television video of 60 frames/second. Also in actual broadcasting, a mixture of such telecine video Vt and non-telecine video Vnt is distributed. Therefore, a special process has to be taken especially at the time of switching between the telecine video Vt and the non-telecine video Vnt.
On receiving an input of the above-stated video signal Sv, the decision circuit 220 decides the contents of the video signal Sv to generate internal variables IP_mode and Mode_f. The decision circuit 220 further generates an output flag F specifying the structure of a video signal Si to be outputted based on these internal variables according to the contents of the video signal Sv. Note that the output flag F corresponds to the signal SF.
Specifically, if it is decided that the field of the video signal Sv represents a telecine image, IP_mode=Film is outputted. If otherwise, IP_mode=IP is outputted for indicating a type of video. If it is decided twice in successive two telecine video units Tu that the present field data is identical to the field data two fields before (two control cycles before), it is decided that the video signal Sv represents telecine video, and IP_mode =Film is outputted. Otherwise, IP_mode=IP is outputted. As such, decision as to the telecine video Vt is inevitably delayed by at least two control cycles with respect to changes in the actual contents of the video signal Sv.
Also, once it is decided that the field of the video signal Sv comes to represent a telecine image, five fields including the field at the time of decision and thereafter are assumed to form the telecine video unit Tu. When it is decided that a third field that follows thus-assumed telecine video unit Tu is not identical to a field that comes two fields thereafter, the field is decided to be the non-telecine video Vnt, and IP_mode=IP is outputted. Decision as to the non-telecine video Vnt is inevitably delayed by at least 2 control cycles with respect to changes in the actual contents of the video signal Sv. That is, the value of IP_mode and the contents of the video signal Sv do not completely coincide with each other.
Mode_f indicates, with numerals 0 through 4, a position of each field in a telecine pattern repeated every five fields within the telecine video unit Tu, if the field of the video signal Sv possibly represents a telecine image. The output flag F produces an output with a numeral 0 or 1 based on the values of IP_mode and Mode_f for indicating how to construct the video signal Si. That is, if the output flag F indicates 0, the inputted video signal Sv is assumed to represent the non-telecine video Vnt, and an instruction is given for constructing the video signal Si. If the output flag F indicates 1, the inputted video signal Sv is assumed to represent the telecine video Vt, and an instruction is given for constructing the video signal Si.
The operation of the above-stated telecine video signal detector Dtc is specifically described below by control cycle.
(Cc1 through Cc5: Telecine video unit Tu1)
First, during the control cycles Cc1 through Cc5, the video signal Sv represents telecine video Vt forming the telecine video unit Tu1. Each identical pieces of field data B1 is placed in the control cycles Cc3 and Cc5.
However, the operation of the decision circuit 220 has just began, and the above-described decision condition of the telecine video Vt xe2x80x9cwhen it is decided twice in successive two telecine video units Tu that the present field data is identical to field data two fields before (two control cycles before), the video signal Sv represents telecine videoxe2x80x9d is not satisfied. Therefore, IP_mode=IP is outputted every control cycle.
As a result, Mode_f=0 and the output flag F=0. In the control cycle Cc1, the video signal Si is not generated. On the other hand, in the control cycle Cc2, an instruction is given for generating the video signal Si for one frame from the field data A1 provided in the control cycle Cc1 and its delayed field data A1 by one field (control cycle). Similarly, the video signal Si in the control cycles Cc3 to Cc5 is composed of the field data A2 (Cc2) and its delayed field data A2xe2x80x2, the field data B1 (Cc3) and its delayed field data B1xe2x80x2, the field data B2 (Cc4) and its delayed field data B2xe2x80x2, and the field data B1 (Cc5) and its delayed field data B1xe2x80x2, and is outputted as delayed by one field (control cycle) during the control cycles Cc4, Cc5, and Cc6.
(Cc6 through Cc10: Telecine video unit Tu2)
During the control cycles Cc6 through Cc9, the condition for deciding that the video signal Sv represents the telecine video Vt is not still satisfied. Therefore, over the control cycles Cc6 through Cc9, the video signal Sv represents the telecine video Vt, but, nevertheless, IP_mode=IP is outputted. On the other hand, the field data B1 in the control cycle Cc5 of the telecine video unit Tu1 is identical to the field data two fields before (in one control cycle Cc3). Therefore, the telecine video unit Tu2 possibly represents the telecine video Vt, and Mode_f=1 (Cc6), 2 (Cc7), 3 (Cc8), and 4 (Cc9) are outputted.
Then, the field data D2 in the control cycle CC10 is identical to the field data two fields before (Cc8), and the condition xe2x80x9cwhen it is decided twice in successive two telecine video units Tu that the present field data is identical to field data two fields before, the video signal Sv represents telecine videoxe2x80x9d is satisfied. Therefore, IP_mode=Film is outputted.
As a result, in the control cycle Cc10, Mode_f=0 and the output flag F=1 are outputted.
Consequently, during the control cycles Cc6 through Cc9, the video signal Si is composed of the field data C2 (Cc6) and its delayed field data C2xe2x80x2, the field data C1 (Cc7) and its delayed field data C1xe2x80x2, the field data D2 (Cc8) and its delayed field data D2xe2x80x2, and the field data D1 (Cc9) and its delayed field data D1xe2x80x2, and is outputted in the control cycles Cc7 to Cc10, respectively.
However, in the control cycle Cc10, IP_mode=Film and Mode_f=0. Therefore, the output flag F=1 is outputted. As a result, the video signal Si composed of the same-source field data D2 and D1 is outputted in the control cycle Cc11.
(Cc11 through Cc15: Telecine video unit Tu3)
During the control cycles Cc11 through Cc15, the video signal Sv still represents the telecine video Vt. Therefore, IP_mode=Film is outputted and, as for Mode_f, 1 (Cc11), 2 (Cc12), 3 (Cc13), 4 (Cc14), and 0 (Cc15) are outputted. Consequently, the output flag F=1 is continued to be outputted.
Based on the output flag F=1, as in the preceding telecine video unit Tu2, in the present telecine video unit Tu3, the field data in the present control cycle and the field data in the previous control cycle form a frame (Si) in the next control cycle for output.
(Cc16 through Cc19: Telecine video unit Tu4)
During the control cycles Cc16 through Cc19, the video signal Sv still represents the telecine video Vt. Therefore, IP_mode=Film is outputted and, as for Mode_f, 1 (Cc16), 2 (Cc17), 3 (Cc18), and 4 (Cc19) are outputted. As a result, the output flag F=1 is continued to be outputted. Then, based on the output flag F=1, as in the preceding telecine video unit, the field data in the present control cycle and the field data in the previous control cycle form a frame (Si) in the next cycle for output. Note that, as described above, the telecine video unit Tu4 has not five but four fields as being interrupted at some point.
(Cc20 through Cc22: Non-telecine video unit Vnt)
In the control cycle Cc20 that is originally supposed to a correspond to the fifth field in the preceding telecine video unit Tu4, the field data J2 that has no relation with the field data H2 two fields before is placed. As such, the telecine video unit Tu4 is interrupted.
Thus, during the control cycles Cc20 through Cc22, IP_mode =IP, Mode_f=0, and the output flag F=0 are outputted. As a result, as in the control cycles Cc1 through Cc5, the input field data J2 (Cc20) and its delayed field data J2xe2x80x2, the input field data K1 (Cc21) and its delayed field data K1xe2x80x2, and the input field data L2 (Cc22) and its delayed field data L2xe2x80x2 form the video signal Si.
Next, with reference to a flowchart shown in FIG. 15, the operation of the decision circuit 220 in the case shown in FIG. 14 is described in further detail. When the telecine video signal detector Dtc is energized to start its operation, the decision circuit 220 sets IP_mode, Mode_f, the output flag F, and Counter to each initial value, that is, I_mode=IP, Mode_f=0, the output flag F=0, and Counter=0.
As described in the foregoing, Mode_f is set to 0 (the video signal Sv does not represent telecine video). Therefore, Yes is determined in step S202, and the procedure goes to a next step S204. Note that the telecine video unit counter Counter indicates, in numeral, a position of the telecine video unit that includes the present field in the successive telecine video Vt.
First, in step S202, it is determined whether Mode_f=0.
If Yes, that is, if it is determined that the video signal Sv represents the non-telecine video Vnt, the procedure goes to step S204.
In step S204, it is determined whether the number of motion pixels Npm is smaller than a first threshold Ath. If Yes, it is determined that there is no motion between fields, that is, the video signal represents telecine video. The procedure then goes to step S212.
In step S212, the telecine video unit counter Counter is incremented by 1. The procedure then goes to a next step S214.
In step S214, it is determined whether the value of Counter is larger than a second threshold Bth. Note that, in the example shown in FIG. 14, the second threshold Bth is 1. If Yes, that is, if it is determined that the video signal Sv represents the telecine video Vt, the procedure goes to step S216.
In step S216, IP_mode=Film is outputted. The procedure then goes to a next step S218.
On the other hand, in step S214, if No, that is, if it is determined that the video signal Sv represents the non-telecine video Vnt, the procedure skips step S216 to step S218.
Furthermore, in the above-stated step S202, if No, that is, if it is determined that the video signal Sv represents the telecine video Vt, the procedure goes to step S218.
In step S218, only Mode_f is incremented by 1. The procedure then goes to a next step S220.
In step S220, Mode_f is divided by 5 and a remainder is calculated. As a result, even if the value of Mode_f is larger than 5, this value is always adjusted to takes 4 or smaller number. This process is to identify the position of the present video signal Sv in the five-field unit (telecine video unit Tu), as telecine video is formed in a fixed pattern as a unit of five fields. In this case, Mode_f=1 is obtained. Then, the procedure goes to a next step S222.
On the other hand, in the above step S204, if No, that is, if it is determined that the video signal represents the non-telecine video Vnt with a motion in image between fields, the procedure goes to step S206.
In step S206, the telecine video unit counter Counter is set to 0. The procedure then goes to a next step S208.
In step S208, IP_mode=IP is outputted. The procedure then goes to a next step S210.
In step S210, Mode_f=0 is outputted. The procedure then goes to step S222.
In step S222, after the process in step S220 or step S210, it is determined whether IP_mode=Film. If after the process in step S220, IP_mode=Film has been set in step S216, and Yes is naturally determined. Then, the procedure goes to step S226. On the other hand, if after the process in step S210, IP_mode=IP has been set in step S208, and No is naturally determined. Then, the procedure goes to step S224.
In step S224, the value of the output flag F is set to 0. Then, an instruction is made for the video signal Si corresponding in frame structure to the non-telecine video. Then, the procedure returns to step S202 to repeat the above processing.
On the other hand, in step S226, the value of the output flag F is set to 1. Then, an instruction is made for the video signal Si corresponding in frame structure to the telecine video. Then, the procedure returns to step S202 to repeat the above processing.
Next, with reference to FIG. 16, the operation of the decision circuit 220 shown in FIG. 13 for each control cycle is described in detail based on the flow chart shown in FIG. 15. Note that shown in FIG. 16 are values of the parameters in each step in the flow chart of FIG. 15.
As described above, when the decision circuit 220 starts to operate, the parameters in the decision circuit 220 are set to initial values (IP_mode=IP, Mode_f=0, the output flag F =0, and the telecine video unit counter Counter=0).
Therefore, in the control cycle Cc1, the field data A1 of the telecine video Vt is provided for process. However, since the operation has just begun, Yes in step S202, No in step S204 (due to no field data for motion comparison), Counter=0 in step S206, IP_mode=IP in step S208, Mode_f=0 in step S210, No in step S222, and then F=0 in step S224.
During the control cycles Cc2 through Cc4, the field data A2 (Cc2), B1 (Cc3), and B2 (Cc4) of the telecine video Vt are provided, and the same processing as that in the above-described control cycle Cc1 is carried out. However, fields data to be compared in step S204 are the field data A1 and the data B1 (Cc3), and the field data A2 and B2 (Cc4).
In the control cycle Cc5, the field data B1 of the telecine video Vt is provided for process. Consequently, Yes in step S202, Yes in step S204 (the field data B1 and B1 are for motion comparison), Counter=1 in step S212, No in step S214, Mode_f =1 in steps S218 and S220, No in step S222, and then F=0 in S224.
In the control cycle Cc6, the field data C2 of the telecine video Vt is then provided for process. Consequently, No in step S202, Mode_f=2 in step S220, No in step S222, and then F=0 in S224.
During the control cycles Cc7 through Cc9, the field data C1, D2, and D1 are then provided for process. Consequently, as in the control cycle Cc6, the procedure goes to steps S202, S218, S220, S222, and then S224. As the control cycle advances, the value of Mode_f changes as 3, 4, 0, respectively. Note that the value of the output flag F in step S224 is 0.
In the control cycle Cc10, the field data D2 identical to the field data two fields before (Cc8) is provided. Consequently, as in the control cycle Cc5, the same field data is detected, and the condition xe2x80x9cwhen it is decided twice in successive two telecine video units Tu that the present field data is identical to field data two fields before (two control cycles before), the video signal Sv represents telecine videoxe2x80x9d is satisfied. Therefore, Yes in step S202, Yes in step S204, Counter=2 in step S212, Yes in step S214, and IP_mode=Film is set in step S216. Then, Mode_f =1 after steps S218 and S220, Yes in step S222, and the output flag F=1 is set in step S226.
Thereafter, during the control cycles Cc11 through Cc19, No in step S202, Yes in step S222 after steps S218 and S220, and then the output flag F=1 is outputted in S226. Note that, during these cycles, instep S220, 2 (Cc11, Cc16), 3 (Cc12, Cc17), 4 (Cc13, Cc18), 0 (Cc14, Cc19) are outputted, respectively, as the value of Mode_f. Also, in the control cycle Cc15, the value of the telecine video unit counter Counter is incremented to 3 in step S212.
The processing during the control cycles Cc20 through Cc22 is similar to that in the above-described control cycle Cc3.
As such, the video signal Si correctly structured in frame can be generated from the video signal Sv which is a mixture of the non-telecine video Vnt and the telecine video Vt.
With the above structure, however, for a field the motion vectors of the same value for one frame is not larger than a predetermined value, whether the signal is a telecine video signal or not cannot be decided. Therefore, especially if part of the telecine signal is missing due to editing or the like, the part cannot be detected. Thus, the signal may be erroneously detected as a telecine signal for four fields at maximum that are assumed to correspond to the telecine video unit Tu.
With reference to FIG. 17, the above-mentioned problem is specifically described. In FIG. 17, as in FIG. 14, Cc61 through Cc7l each represent a control cycle in the telecine video signal detector Dtc. The video signal Sv is provided in order of field data E2, F1, F2, F1, G2, G1, H2, I1, J2, K1, and L2 for each field period. In this case, the video signal Sv represents the telecine video Vt during the control cycles Cc61 through Cc67, while indicating the non-telecine video VnT during the control cycles Cc68 through Cc71.
Note that, during the control cycles Cc61 through Cc71 except for the control cycle Cc68, the field data identical to those during the control cycles Cc12 through Cc22 in FIG. 14 are provided. In the control cycle Cc68, however, as a result of editing, not the same-source field data H2 as the previous field data H1 but the field data I1 of a different image is provided. Although not shown, in the control cycle previous to the control cycle Cc61, the telecine video Vt is provided.
That is, the control cycles Cc60 through Cc64 form a complete telecine video unit Tux (x is an arbitrary integer). During the preceding control cycles through the control cycle Cc64, the above-mentioned condition xe2x80x9cwhen it is decided twice in successive two telecine video units Tu that the present field data is identical to field data two fields before (two control cycles before), the video signal Sv represents telecine videoxe2x80x9d is satisfied. Therefore, it is assumed in the control cycle Cc65 that a telecine video unit Tux+1 following the telecine video unit Tux starts. Then, in the successive control cycles Cc65, Cc66, Cc67, and Cc68, as in the control cycles Cc16 through Cc18, IP_mode=Film, 1, 2, 3, and 4, respectively, as Mode_f, and the output flag F=1 are outputted.
Therefore, in the control cycle Cc68, the output flag F=1. Therefore, the video signal Si originally supposed to be formed of the same-source field data H1 and H2 but actually formed of the telecine field H2 and the different image field data II is outputted in the control cycle Cc69. As a result, the frame image formed of different image field is incomplete and looks bad. Note that, in the control cycle Cc68, the video signal Si is changed in representation to the non-telecine video Vnt. Therefore, the video signal Si is originally supposed to be formed of the field data II and its delayed field data I1xe2x80x2.
In the control cycles Cc69 through Cc71, as in the above-described control cycles Cc20 through Cc22, IP_mode=IP, Mode_f=0, and the output flag F=0 are outputted, and the video signal is correctly formed. As described above, in the conventional telecine video signal detector Dtc, for the telecine video signal Sv produced through 2-3 pulldown conversion, whether the present field data represents a telecine video signal is determined depending on whether the third and fifth of successive five pieces of field data are identical.
Thus, basically, if the telecine video signal Sv is provided with its state being changed to the non-telecine video Vnt while the telecine video unit Tu is incomplete, that is, successive five fields are not yet satisfied, whether the present field data represents the telecine video Vt or non-telecine video Vnt cannot be determined correctly.
Thus, as shown in FIG. 14, if the fifth field of the telecine video unit Tu is missing, the third and fourth field data are the same-source field data in the 2-3 pulldown scheme. For this reason, the present frame generation in telecine video does not cause a problem of image distortion.
As shown in FIG. 17, however, if the fourth or later field data of the telecine video unit Tu is missing, different image field data is placed after the third of the telecine video unit Tu (that is, at the fourth position). Therefore, the video signal Si representing distorted image formed in frame of different image fields is erroneously outputted.
In view of the above problem, an object of the present invention is to provide a telecine video signal detector capable of sequentially detecting even an insuccessive telecine video signal produced due to editing or the like.
To achieve the above objects, the present invention has the following aspects.
A first aspect of the present invention is directed to, in a telecine video signal obtained through conversion into an interlaced signal by a 2-3 pulldown scheme, a telecine video signal detector for detecting, if part of the telecine signal is missing due to editing or the like, the missing part of the telecine signal and deciding whether successive telecine conversion has been carried out, the detector comprising:
a motion detector for detecting a motion of an image between a first field of the telecine video signal and a second field at least one or more fields apart from the first field, and generating a motion detection signal;
a first statistical processing unit for accumulating the motion detection signals for one field, and generating a first statistical signal;
a first telecine decision unit for deciding, based on the first statistical signal, whether the first field represents a telecine-converted image, and generating a first telecine decision signal;
a second statistical processing unit for carrying out a histogram operation with respect to the telecine video signal for one field, and generating a second telecine decision signal including video statistical information;
a 1-field delay unit for delaying the second statistical signal by at least one field, and generating a delayed second statistical signal;
a scene-change detection unit for detecting, based on the second statistical signal, the delayed second statistical signal, and a predetermined threshold, a scene-change in the telecine video, and generating a scene-change detection signal;
a second decision unit for deciding, based on the scene-change detection signal and the first telecine decision signal, whether the first field represents an image produced through successive telecine conversion, and generating a second telecine decision signal; and
an AND operation unit for carrying out an AND operation on the first telecine decision signal and the second telecine decision signal, wherein whether the first field represents the image produced through successive telecine conversion is indicated based on a result of the AND operation.
As described above, in the first, by ANDing the values of the two telecine decision units, it can be successively decided that the signal represents an image produced through telecine conversion. Consequently, if part of the telecine signal is missing due to editing or the like, the part can be detected, and whether successive telecine conversion has been carried out can be decided.
According to a second aspect, in the first aspect, the predetermined threshold is two or more, and the scene-change detection unit adaptively detects the scene-change.
According to a third aspect, in the first aspect, wherein the second statistical processing unit outputs a plurality of second statistical signals,
the scene-change detection unit comprises:
a plurality of scene-change detection circuits for generating a plurality of scene-change detection signals corresponding to the plurality of second statistical signals; and
an OR operation unit provided with the plurality of scene-change detection signals for carrying out an OR operation, and
the scene-change of the video signal is detected with a result of the OR operation on the plurality of scene-change detection signals.
According to a fourth aspect, in the first aspect, the first decision unit comprises a 5-field delay unit for delaying the first statistical signal by five fields, and generates a timing signal, and
the detector comprises a selection unit for selectively outputting one of the first telecine decision signal and the second telecine decision signal based on the timing signal, and successively decides whether the video signal represents video produced through telecine conversion.
According to a fifth aspect, in the fourth aspect, the detector further comprises a 2-field delay unit for further delaying the delayed second statistical signal by two fields and generating a delayed third statistical signal;
a first switch unit for selectively inputting, based on the first telecine decision signal, one of the motion detection signal and the video signal to the first statistical processing unit by a unit of field; and
a second switch unit for outputting a result of accumulation of the motion detection signals for one field and a result of a statistical process on the input signal for one field that are carried out only by the first statistical processing unit with a help of the first switch unit switching an input to the first statistical processing unit, and switching, based on an output from a sequence detector, a destination to which the first statistical signal is provided between the first telecine decision unit and the scene-change detection unit.